WO2017094599A1

WO2017094599A1 - Seal device

Info

Publication number: WO2017094599A1
Application number: PCT/JP2016/084899
Authority: WO
Inventors: 晃宏光明; 石橋　信一; 岳洋中川
Original assignee: Nok株式会社
Priority date: 2015-11-30
Filing date: 2016-11-25
Publication date: 2017-06-08
Also published as: US20180259072A1; EP3385579A1; JP6174288B1; EP3385579B1; JPWO2017094599A1; US10711899B2; CN108138965A; CN108138965B; EP3385579A4

Abstract

The invention provides a seal device in which a sealing lip comes into slidable contact with a sealing flange, and a threaded groove, which exhibits fluid-pumping action during rotation, is provided to the sealing flange; wherein static leakage is suppressed. This purpose is achieved by a seal device in which a sealing fluid inside the device does not leak out of the device through space between a housing and a rotating shaft inserted through a shaft hole provided to the housing; the sealing lip, which is fitted into the inner periphery of the shaft hole in the housing, comes into slidable contact with the sealing flange, which is fitted over the outer periphery of the rotating shaft; and a threaded groove, which exhibits a fluid-pumping action when the rotating shaft rotates, is provided to the sealing flange so as to intersect with a lip end of the sealing lip. The seal device is characterized in that the cross-sectional area of the threaded groove is formed so as to be comparatively smaller in a sliding area in the sealing flange with which the sealing lip comes into slidable contact, and comparatively larger in an inner-peripheral area that is nearer to the inner periphery than the sliding area.

Description

Sealing device

The present invention relates to a sealing device that suppresses leakage of a sealing fluid inside a machine to the outside of the machine in an automobile, a general machine, an industrial machine, or the like. The sealing device of the present invention is used, for example, as an oil seal for rotation that seals in-machine oil in the field of automobiles.

Conventionally, as shown in FIGS. 8A and 8B, the sealing fluid on the machine inner side A does not leak to the machine outer side B between the housing 51 and the rotary shaft 61 inserted through the shaft hole 52 provided in the housing 51. A sealing device 101 for sealing such that the slinger 111 is mounted on the outer periphery of the rotating shaft 61 and the lip seal member 121 is mounted on the inner periphery of the shaft hole 52 of the housing 51 located on the machine outer side B of the slinger 111. A sealing device 101 that is a combination of the above and the like is known.

The slinger 111 is made of a rigid material such as metal, and has a cylindrical portion 112 fitted to the outer peripheral surface of the rotating shaft 61 and a seal flange 113 provided at one end of the cylindrical portion 112. A screw groove 114 is provided on the machine-side end face 113a of the seal flange 113 to exert a fluid pumping action by centrifugal force during rotation.

On the other hand, the lip seal member 121 has an attachment ring 122 fitted to the inner peripheral surface of the shaft hole 52 of the housing 51 and a rubber-like elastic body 123 attached to the attachment ring 122. The body 123 is provided with a seal lip (end surface lip) 124 that slidably contacts the machine-side end surface 113 a of the seal flange 113 in the slinger 111.

The sealing device 101 configured as described above seals the sealing fluid by the slidable contact of the seal lip 124 with the machine outer end surface 113a of the seal flange 113, and the screw groove 114 provided on the machine outer end surface 113a of the seal flange 113. Exhibits a fluid pumping action by centrifugal force during rotation and pushes the sealing fluid back to the machine interior A, so that an excellent sealing effect can be exhibited.

Japanese Utility Model Publication No. 3-57563 Japanese Patent Laid-Open No. 2-113173 JP 2014-1229837 A

However, the sealing device 101 is required to be further improved in the following points.

That is, in the sealing device 101, as described above, the sealing lip 124 is slidably brought into contact with the machine outer end surface 113a of the seal flange 113 to seal the sealing fluid and is provided on the machine outer end surface 113a of the seal flange 113. Since the thread groove 114 exerts a fluid pumping action due to centrifugal force during rotation and pushes the sealing fluid back to the machine interior A, an excellent sealing effect can be exhibited. It is arranged to cross the lip end. Therefore, when the rotation of the rotary shaft 61 stops and the centrifugal force disappears, and the fluid pumping action by the thread groove 114 is not exhibited along with this, the sealing fluid travels along the thread groove 114 and moves the lip end of the seal lip 124. There is concern about the passage from the outer peripheral side to the inner peripheral side and leakage to the outboard side B (so-called stationary leakage occurs).

In view of the above points, the present invention has a static leak in a sealing device in which a seal lip is slidably in contact with a seal flange and a thread groove is provided on the seal flange to exert a fluid pumping action during rotation. It is an object of the present invention to provide a sealing device that can suppress this.

In order to achieve the above object, the present invention employs the following means.
The sealing device of the present invention is a sealing device that seals a sealing fluid inside the machine from leaking to the outside of the machine between a housing and a rotary shaft that is inserted into a shaft hole provided in the housing. The seal lip attached to the inner periphery of the shaft hole of the housing slidably contacts the seal flange attached to the housing, and a thread groove that exerts a fluid pumping action when the rotary shaft rotates is a lip of the seal lip. In the sealing device provided in the seal flange so as to intersect with the end, a cross-sectional area of the thread groove is relatively small in a sliding region where the seal lip in the seal flange is slidably contacted, It is characterized in that it is formed relatively large in the inner peripheral side region on the inner peripheral side with respect to the sliding region (claim 1).

According to the sealing device of the present invention, the cross-sectional area of the screw groove is formed smaller than the inner peripheral area in the sliding region, and if the cross-sectional area of the screw groove is small, it is difficult for the sealing fluid to flow. It becomes difficult to do. In addition, the thread groove has a cross-sectional area that is larger than the sliding area in the inner peripheral region, and if the cross-sectional area is large, the sealing fluid can easily flow, so that the amount of fluid pumping by the fluid pumping action can be increased. Become. Therefore, it is possible to provide a sealing device in which stationary leakage is less likely to occur compared to the case where the cross-sectional area of the thread groove is constant over the entire length of the thread groove, and the fluid pumping action is almost the same. In addition, the cross-sectional area of a screw groove means the cross-sectional area when a screw groove is cut | disconnected in the direction orthogonal to the longitudinal direction. Similarly, the cross-sectional shape of the thread groove means a cross-sectional shape when the thread groove is cut in a direction orthogonal to the longitudinal direction.

The aspect of the cross-sectional shape of the thread groove is an aspect in which the groove depth is constant over the entire length of the thread groove, the groove width is relatively small in the sliding region, and relatively large in the inner peripheral region (Claims). 2) and a mode in which the groove width is constant over the entire length of the thread groove, the groove depth is relatively small in the sliding region, and relatively large in the inner peripheral region (Claim 3). Also, by combining both aspects, the groove width is relatively small in the sliding region and relatively large in the inner peripheral region, and the groove depth is relatively small in the sliding region, and relatively small in the inner peripheral region. It can be considered to be formed large. The groove width and depth are assumed to change stepwise or gradually.

According to the present invention, in a sealing device in which a seal lip is slidably contacted with a seal flange and a thread groove that exhibits a fluid pumping action during rotation is provided in the seal flange, occurrence of static leakage is suppressed. can do.

Sectional drawing of the principal part of the sealing device which concerns on 1st Example of this invention. It is explanatory drawing of the thread groove with which the same sealing device is equipped, Comprising: C direction arrow line view in FIG. It is sectional drawing of the screw groove, (A) is sectional drawing of the screw groove in a sliding area, (B) is sectional drawing of the screw groove in an inner peripheral side area | region. It is sectional drawing of the screw groove with which the sealing apparatus which concerns on 2nd Example of this invention is equipped, Comprising: (A) is sectional drawing of the screw groove in a sliding area | region, (B) is a cross section of the screw groove in an inner peripheral area | region. Figure Explanatory drawing showing another example of thread groove shape Sectional drawing of the principal part of the sealing device which concerns on the reference example of this invention It is explanatory drawing of the pumping flow path with which the sealing device is equipped, Comprising: The D direction arrow line view in FIG. It is a figure which shows a prior art example, (A) is principal part sectional drawing of the sealing device which concerns on a prior art example, (B) is explanatory drawing of the screw groove with which the sealing device is equipped.

Next, embodiments of the present invention will be described with reference to the drawings.

First embodiment
1 to 3 show a sealing device 1 according to an embodiment of the present invention.

In the sealing device 1 according to this embodiment, the sealing fluid (oil or the like) on the machine inner side A is between the housing (seal housing) 51 and the rotary shaft 61 inserted through the shaft hole 52 provided in the housing 51. A sealing device (for example, an engine oil seal) 1 for sealing so as not to leak into the shaft, a slinger 11 mounted on the outer periphery of the rotary shaft 61, and a shaft hole 52 of the housing 51 located on the outside B of the slinger 11. It is comprised by the combination with the lip seal member 21 with which inner periphery is mounted | worn.

The slinger 11 is made of a rigid material such as metal, and has a cylindrical portion (sleeve portion) 12 that is fixed (fitted) to the outer peripheral surface of the rotating shaft 61 and one end of the cylindrical portion 12 (end on the machine inner side). And a radially outward seal flange (flange portion) 13 provided on the outer surface 13a of the seal flange 13 and pumped by centrifugal force when the rotary shaft 61 rotates as shown in FIG. A spiral thread groove 14 is provided that exerts an action of pushing back the sealing fluid toward the outer peripheral side (machine inner side A) by exerting the action. An arrow e indicates the rotation direction of the rotation shaft 61. The machine end face 13a and the thread groove 14 of the seal flange 13 will be described in detail later.

On the other hand, the lip seal member 21 is attached (vulcanized and bonded) to the mounting ring 22 made of a rigid material such as metal that is fixed (fitted) to the inner peripheral surface of the shaft hole 52 of the housing 51. An outer peripheral seal portion 27 that seals between the housing 51 and the mounting ring 22 by contacting the inner peripheral surface of the shaft hole 52 of the housing 51, and the rubber-like elastic body 26. An end surface adhering portion 28 adhering to the end surface portion of the ring 22, a seal lip (end surface lip) 29 slidably contacting the outboard end surface 13 a of the seal flange 13 in the slinger 11, A contact grease storage lip 30 is integrally provided. The seal lip 29 is slidably in contact with the outboard end surface 13a of the seal flange 13 with the lip end 29a, and the lip end 29a of the seal lip 29 and the screw groove 14 are arranged to intersect each other. In addition, a dust lip 31 is attached to the inner peripheral side of the end surface adherent portion 28, and this dust lip 31 is made of fabric, but is integrally provided by the rubber-like elastic body 26. It may be.

The mounting ring 22 has an outer peripheral cylindrical portion 23 fixed (fitted) to the inner peripheral surface of the shaft hole 52 of the housing 51, and a radially inwardly provided at one end (outside end portion) of the outer peripheral cylindrical portion 23. The flange portion 24 is integrally provided.

Further, particularly in the embodiment, the machine end face 13a and the screw groove 14 of the seal flange 13 are configured as follows.

That is, as shown in FIG. 2, the seal flange 13 is provided with a thread groove forming region 15 in which a thread groove 14 is formed on its outer end surface 13a. The thread groove forming region 15 is an annular region comprising a predetermined radial width h _0. The thread groove forming region 15 includes a sliding region 15A where the seal lip 29 is slidably contacted, an outer peripheral region 15B on the outer peripheral side of the sliding region 15A, and an inner peripheral side of the sliding region 15A. It is divided into an inner peripheral region 15C. Sliding region 15A is an annular region comprising a predetermined radial width h _1. Outer circumferential region 15B is an annular region comprising a predetermined radial width h _2. The inner peripheral side region 15C This is also an annular region comprising a predetermined radial width h _3.

In FIG. 2, four screw grooves 14 are provided at equal intervals on the circumference, but since all have the same configuration, only one will be described.

The screw portion 14 is formed as a groove having a length from the outer peripheral end portion of the outer peripheral side region 15B to the inner peripheral end portion of the inner peripheral side region 15C via the sliding region 15A.

Further, the thread groove 14 is formed to have a relatively small cross-sectional area in the sliding region 15A and relatively large in the inner peripheral side region 15C. More specifically, as shown in FIG. 14, the groove depth d is constant over the entire length of the thread groove, and the groove width is formed to be relatively small in the sliding region 15A as shown in FIG. are relatively larger in the inner region 15C as shown in _{(w 1} a groove width in the sliding region 15A, the groove width at the inner peripheral side region 15C as _{_{_{w 2, w 1 <w 2}}} ).

Such a thread groove 14 is formed, for example, by setting its cross-sectional area so as to gradually expand from the outer peripheral end portion of the outer peripheral side region 15B to the inner peripheral end portion of the inner peripheral side region 15C. The groove width is similarly set by gradually increasing from the outer peripheral end portion of the outer peripheral side region 15B to the inner peripheral end portion of the inner peripheral side region 15C.

In the sealing device 1 configured as described above, when the rotary shaft 61 rotates, the seal lip 29 exerts a sealing function by slidably contacting the lip end 29a with the machine end surface 13a of the seal flange 13 of the slinger 11. In addition, since the slinger 11 rotating together with the rotating shaft 61 exerts a fluid swinging action by the seal flange 13 and a fluid pumping action by the screw groove 14, even if there is a fluid passing between the seal lip 29 and the seal flange 13, It is possible to push back to the side (machine inner side A), and thus an excellent sealing function is exhibited.

Further, when the rotation of the rotating shaft 61 stops, the centrifugal force disappears, and the fluid swinging action and the fluid pumping action are temporarily stopped along with this, so that a part of the sealing fluid travels through the screw groove 14 from the machine inner side A. There is a concern that the seal lip 29 may flow into the inner circumferential space 32. However, in the sealing device 1, the cross-sectional area of the thread groove 14 is smaller than the inner circumferential region 15C in the sliding region 15A. Since the sealing fluid does not easily flow through the screw groove 14 having a small area, the sealing fluid does not easily flow from the machine inner side A to the inner peripheral space 32 of the seal lip 29 through the screw groove 14. Therefore, it is possible to suppress the occurrence of stationary leakage, and at least the amount of stationary leakage can be reduced.

Further, in the sealing device 1 having the above configuration, the cross-sectional area of the screw groove 14 is formed larger than the sliding area 15A in the inner peripheral region 15C, and the sealing fluid easily flows through the screw groove 14 having a large cross-sectional area. It is possible to increase the amount of fluid pumping by the fluid pumping action.

Therefore, it is possible to provide a sealing device in which stationary leakage is less likely to occur compared to the case where the cross-sectional area of the thread groove 14 is constant over the entire length of the thread groove, and the fluid pumping action is almost the same.

Second embodiment ...
In the first embodiment, the cross-sectional shape of the thread groove 14 is such that the groove depth d is constant over the entire length of the thread groove, the groove width is relatively small in the sliding region 15A, and relatively large in the inner peripheral side region 15C. Although there is a manner to be formed _(w 1 _<w _2), in addition, a constant groove width over the thread groove full length, groove depth is relatively small in the sliding region 15A, the inner peripheral side region It may be a mode in which a relatively large shape is formed at 15C.

In FIG. 4, as an example of this mode, the groove width w is constant over the entire length of the thread groove, and the groove depth is formed relatively small in the sliding region 15A as shown in FIG. a groove depth in a relatively large formed (sliding region 15A _{d 1,} the groove depth at the inner peripheral side region 15C as _{d 2} in the inner region 15C as shown in 4 (B), _{d 1} <D ₂ ).

Such a thread groove 14 is formed, for example, by setting the groove depth to gradually expand from the outer peripheral end portion of the outer peripheral side region 15B to the inner peripheral end portion of the inner peripheral side region 15C. .

In the first and second embodiments, the screw groove 14 has a triangular cross-sectional shape, but the cross-sectional shape of the screw groove 14 is not particularly limited. It may be.

Further, in the first and second embodiments, the screw groove 14 has a curved planar shape (shape in the direction of the arrow C), but the planar shape of the screw groove 14 may be linear. . Further, the screw groove 14 is not limited to a spiral shape, and may be a radial shape provided with a plurality of radial grooves (eight in the drawing) as shown in FIG.

Next, the invention according to the reference example will be described.

Problems to be solved by the invention ...
An object of the invention according to the reference example is to provide a sealing device in which a sealing lip is slidably brought into contact with a sealing flange and has a structure that exhibits a fluid pumping action and is less likely to cause static leakage. .

Means for solving the problems ...
The invention according to the reference example employs the following means in order to achieve the above object.
That is, the invention according to the reference example is a sealing device that seals a sealing fluid inside the machine from leaking to the outside of the machine between a housing and a rotary shaft that is inserted into a shaft hole provided in the housing. In a sealing device in which a seal lip mounted on the inner periphery of the shaft hole of the housing is slidably brought into contact with a seal flange mounted on the outer periphery, a pumping flow path comprising a screw pattern in which fine irregularities are continuously arranged Is provided on the outer end surface of the seal flange so as to intersect the lip end of the seal lip.

According to the invention according to this reference example, as an alternative to the conventional thread groove, the seal flange machine is constructed so that the pumping flow path made of a screw pattern in which fine irregularities are continuously arranged intersects the lip end of the seal lip. Provided on the outer end face, this pumping flow path exerts a fluid pumping action by centrifugal force during rotation to push the sealed fluid back to the inside of the machine.

In addition, the pumping flow path formed of a continuous body of fine irregularities has a larger flow resistance when a sealed fluid flows compared to a thread groove having a constant depth in the length direction. Therefore, it is difficult for the sealing fluid to flow, and static leakage is unlikely to occur.

The unevenness is made up of, for example, an electric discharge machining trace, a press machining trace, a shot blasting trace, or a laser machining trace.

The invention's effect····
According to the invention according to the reference example, in the sealing device in which the seal lip is slidably contacted with the seal flange, it is possible to provide a sealing device having a structure that exhibits a fluid pumping action and hardly generates a stationary leak. .

DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the invention according to a reference example will be described with reference to the drawings.

6 and 7 show a sealing device 1 according to an embodiment of the invention according to the reference example.

The sealing device 1 according to the embodiment of the invention according to the reference example includes a sealing fluid (oil or the like) inside the machine A between a housing (seal housing) 51 and a rotary shaft 61 inserted into a shaft hole 52 provided in the housing 51. ) Is a sealing device (for example, an engine oil seal) 1 for sealing so as not to leak to the outside B, and a slinger 11 mounted on the outer periphery of the rotary shaft 61 and a housing located on the outside B of the slinger 11 It is comprised by the combination with the lip seal member 21 with which the axial hole 52 of 51 is mounted | worn.

The slinger 11 is made of a rigid material such as metal, and has a cylindrical portion (sleeve portion) 12 that is fixed (fitted) to the outer peripheral surface of the rotating shaft 61 and one end of the cylindrical portion 12 (end on the machine inner side). ) And a radially outward seal flange (flange portion) 13 provided integrally therewith.

On the other hand, the lip seal member 21 is attached (vulcanized and bonded) to the mounting ring 22 made of a rigid material such as metal that is fixed (fitted) to the inner peripheral surface of the shaft hole 52 of the housing 51. An outer peripheral seal portion 27 that seals between the housing 51 and the mounting ring 22 by contacting the inner peripheral surface of the shaft hole 52 of the housing 51, and the rubber-like elastic body 26. An end surface adhering portion 28 adhering to the end surface portion of the ring 22, a seal lip (end surface lip) 29 slidably contacting the outboard end surface 13 a of the seal flange 13 in the slinger 11, A contact grease storage lip 30 is integrally provided. The seal lip 29 slidably contacts the machine end surface 13a of the seal flange 13 with its lip end 29a. In addition, a dust lip 31 is attached to the inner peripheral side of the end surface adherent portion 28, and this dust lip 31 is made of fabric, but is integrally provided by the rubber-like elastic body 26. It may be.

In the embodiment of the invention according to the reference example, in particular, a pumping flow path 16 made of a screw pattern in which fine irregularities are continuously arranged as shown in FIG. Yes. The pumping flow path 16 exerts an action of pushing back the sealing fluid toward the outer peripheral side (machine inner side A) by exerting a pumping action by centrifugal force when the rotating shaft 61 rotates. It is configured.

That is, the pumping flow path 16 is formed in a spiral shape by being arranged in a strip shape having a predetermined length and width in which a large number of fine irregularities are continuously arranged. In FIG. 7, four pumping channels 16 are provided at equal intervals on the circumference, but the number is not particularly limited. The direction of the screw or spiral is such that the outer peripheral end portion 16 b is displaced rearward with respect to the rotational direction e of the rotary shaft 61 rather than the inner peripheral end portion 16 a of the flow path 16. The pumping flow path 16 is disposed so as to intersect the lip end 29 a of the seal lip 29.

The fine irregularities are formed by an electric discharge machining method, a press machining method, a shot blasting method or a laser machining method, and are formed as an electric discharge machining mark, a press machining mark, a shot blasting mark or a laser machining mark. Among these processing methods, the electric discharge processing method and the laser processing method are particularly suitable for processing uneven patterns because local processing can be easily performed. In addition, there is an advantage that the impact due to processing is small and the dimensional change of the slinger 11 hardly occurs.

The machine outer end surface 13a of the seal flange 13 is formed as a smooth surface, and the pumping flow path 16 made of a continuous body (band) of fine irregularities is formed on the machine outer end surface 13a made of this smooth surface.

In the sealing device 1 configured as described above, when the rotary shaft 61 rotates, the seal lip 29 exerts a sealing function by slidably contacting the lip end 29a with the machine end surface 13a of the seal flange 13 of the slinger 11. In addition, the slinger 11 that rotates together with the rotating shaft 61 exerts a fluid swinging action by the seal flange 13, and the pumping flow path 14 provided on the outer end surface 13 a of the seal flange 13 exerts the fluid pumping action as described above. . Therefore, an excellent sealing effect is exhibited.

Further, when the rotation of the rotating shaft 61 stops, the centrifugal force disappears, and the fluid swinging action and the fluid pumping action are temporarily stopped accordingly. However, the pumping flow path 16 has a sealed fluid flowing in the pumping flow path 16 as compared with the thread groove having a constant depth in the length direction according to the prior art. When the flow resistance is large. Therefore, since the sealing fluid hardly flows to the pumping flow path 16, it is possible to suppress the occurrence of stationary leakage, or at least reduce the amount of stationary leakage. Since the bottom surface of the pumping flow path 16 is not a flat surface but an uneven surface, a sealing fluid such as oil having a predetermined viscosity is difficult to flow through the pumping flow path 16.

DESCRIPTION OF SYMBOLS 1 Sealing device 11 Slinger 12 Cylindrical part 13 Seal flange 13a Machine outer side end surface 14 Screw groove 15 Screw groove formation area 15A Sliding area 15B Outer peripheral area 15C Inner peripheral area 16 Pumping flow path 16a Inner peripheral end 16b Outer peripheral end DESCRIPTION OF SYMBOLS 21 Lip seal member 22 Mounting ring 23 Outer peripheral cylinder part 24 Flange part 26 Rubber-like elastic body 27 Outer peripheral seal part 28 End surface covering part 29 Seal lip 29a Lip end 30 Grease storage lip 31 Dustrip 32 Inner peripheral side space 51 Housing 52 Shaft hole 61 Rotating shaft A Machine inside B Machine outside

Claims

A sealing device for sealing so that a sealing fluid inside the machine does not leak to the outside of the machine between a housing and a rotary shaft inserted through a shaft hole provided in the housing,
A seal lip attached to the inner periphery of the shaft hole of the housing slidably contacts the seal flange attached to the outer periphery of the rotating shaft,
In the sealing device provided in the seal flange such that a thread groove that exerts a fluid pumping action at the time of rotation of the rotating shaft intersects the lip end of the seal lip,
The cross-sectional area of the thread groove is relatively small in a sliding area where the seal lip in the seal flange contacts slidably, and relatively large in an inner peripheral area closer to the inner side than the sliding area. A sealing device characterized by being formed.
The sealing device according to claim 1.
The screw groove has a groove depth that is constant over the entire length of the screw groove, and a groove width that is relatively small in the sliding region and relatively large in the inner peripheral region. Sealing device characterized.
The sealing device according to claim 1.
The screw groove has a groove width that is constant over the entire length of the screw groove, a groove depth that is relatively small in the sliding region, and relatively large in the inner peripheral region. Sealing device characterized.